This happened to my Emerald too. Did the Game Pak become dislodged when you were playing? If so, it means you have to save twice instead of once for while, then experiment by saving once. If you appear in a different place to where you last saved then continue to save twice; otherwise your game will be fixed. i don't know if this will work for yours, it did for mine so give it a go and see what happens. Even if it didn't become dislodged try this anyway.

If not the above then it's a fake game sadly as normal legit games will not display such a message unless it's broken in some odd way, but it is more likely it is fake. Nothing you can do about it either short of finding a legit copy...

A parody of the Pokemon Colosseum game, full of pastries and Miror B.
Completed. Four times winner of Best Comedy/Funniest Fic.Avatar: minty-fivestar on DA, edited background/cropping. Fic banner: cieux.